The present disclosure relates to completing well systems.
In certain well completions, the completion string includes a float shoe at its lower, downhole end that operates as a check valve, allowing fluids to flow out of the completion string, but not allowing fluids to flow into the completion string. The float shoe enables circulation of fluids into the wellbore, such as with washdown and other fluid displacement operations. In a washdown operation, a working string, called a washpipe, is run into the completion string and completion fluids are pumped down through the working string and up through the annulus to displace debris and drilling fluids in the wellbore. Typically, once the washdown is complete, the ability to flow fluids out of the float shoe is not needed. Therefore, a valve, commonly operated with a shifting tool, can be provided above the float shoe to isolate the float shoe from the remainder of the completion string. The closed valve serves as a secondary shutoff of the float shoe, and particularly in an injection well, prevents the float shoe from opening again.
Prior to putting the well on production or injection, the completion string is pressure tested. Also, in some instances there is a need to seal a portion of the completion string from producing fluids to the surface. A reservoir isolation valve is provided in the completion string to seal the producing portions of the completion string from the remaining portions. Some reservoir isolation valves close on withdrawal of the washpipe, and can be reopened in response to a remote pressure signal and/or with a shifting tool.
Like reference symbols in the various drawings indicate like elements.